The analyses of heavy minerals and their assemblages were carried in practice for two field sections in the southern Junggar Basin, well cores data and two field sections in the inner Tianshan Mountains. Different heavy minerals' assemblages and increasing of unstable heavy minerals during Late Jurassic-earliest Cretaceous, Late Cretaceous and Late Cenozoic might indicate tectonic activity during these three periods. There existed three provenance systems in the southern Junggar Basin and several separated small basin within the Tianshan Mountains during Early-Middle Jurassic. The characteristics of sedimentary systems and heavy minerals proved that the Junggar and Tarim Basins were not physiographically separated by an ancestral version of the Tianshan Mountains during Early-Middle Jurassic. From Late Jurassic to the earliest Cretaceous, the distribution of Upper Jurassic Kalazha conglomerate and Cretaceous bottom conglomerate in front of the Bogda Mountains showed a tectonically active setting and obvious uplift of Tianshan during the latest Jurassic-earliest Cretaceous, and the Bogeda Mountains became another provenance system of the southern Junggar Basin, resulting in widely varied sedimentary successions between the Tarim Basin and the southern Junggar Basin. The basin-orogen pattern of the southern Junggar Basin didn't change greatly until the long-distance effect of India-Asia collision. The Mesozoic-Cenozoic tectonic activities and evolution of the basin-orogen pattern in the southern Junggar Basin should be related to the collision in the southern margin of the Eurasia plate.

Abstract A detailed study of sedimentology and stratigraphic evolution of the fan delta at the Sikeshu section in the southern edge of the Junggar basin was conducted. The fan delta of the Badaowan formation is exposed continuously along the cross section, which shows the stratigraphic and geographic distribution of channel complexes, channel conglomerates and coarse sandstones; flood plain mudstones and thin coal seams, and lacustrine mudstones. Eventually, a fan delta sedimentary model has been established based on the reconstruction of sedimentary characteristics. Based on dissection of the section, channel sand bodies can be divided into three types: amalgamated, transitional, and isolated, which correspond to the origin of braided channels, braided channels transforming into distributary channels (transformation part), and distributary channels respectively. The width (W), thickness (T), and width/thickness ratio (W/T) dimensions of the three types of channel sand bodies were measured in the field. The width, thickness, and width/thickness ratio gradually decrease from amalgamated to isolated sand bodies. The characteristics, sedimentology genesis, and variation of sand bodies are controlled by the variation of base-level cycles and their relevant position. The dimensions of channel sand bodies are proportionate to accommodation/sediment supply (A/S) ratio inversely, which the dimensions decrease with the increase in the A/S ratio. Moreover, the proportion, thickness, connectivity, grain size, and dimensions of channel sand bodies decrease in accompany with the rise of base level.

Central Asian Orogenic Belt is the world's Phanerozoic crustal growth and transformation of the most significant areas. It is a giant suture zone formed by Paleo-Asian Ocean subduction which located in between the Siberian Plate and Sino-Korean, Tarim Plate.Northern Xinjiang is located in the southern section of Central Asian Orogenic Belt. Today It presents a basin and range landscape. Junggar Basin is located between the Altai Mountain and Tianshan(Figure 1). Paleozoic tectonic evolution of northern Xinjiang to become a hot research topic, however, following the closure of the Paleo-Asian Ocean tectonic evolution of intracontinental, in particular Uplift history of the margin of the Junggar Basin is not clear. This paper attempts by the margin of the Junggar Basin, Late Paleozoic magmatic rocks of the apatite, zircon fission-track studies, to reveal the law of uplift of margin of the Junggar Basin since the Mesozoic. PIC

The Junggar Basin, located in northwestern China, provides important records for investigating Mesozoic tectonic and climate evolution in Central Asia. The Upper Jurassic-lowermost Cretaceous strata in the basin include the Qigu, Kalazha, and Qingshuihe Formations in ascending order. By synthesizing outcrop and well data and previous research, we conducted a detailed sedimentologic and stratigraphic correlation analysis for the three formations. Our study shows that a sharp lithofacies change from intermittent braided-river red fine-grained sediments of the Qigu Formation to alluvial fan conglomerates of the Kalazha Formation, is widespread along the basin margins. From bottom to top, the Kalazha alluvial fan conglomerates can be divided into six sequences showing a progradation to retrogradation cycle, and they finally retrograde into the lake sediments of the lowermost Cretaceous Qingshuihe Formation. However, within the Junggar Basin, the Kalazha Formation is commonly considered to be absent and the Qingshuihe Formation possesses a basal fluvial coarse-grained sandstone bed (50 100m), beneath which a widespread unconformity is observed. Stratigraphic correlation suggests that the alluvial fan conglomerates of the Kalazha Formation along the basin margins are equivalent to the basal sandstone bed of the Qingshuihe Formation within the basin. Finally, we conclude that progressive tectonic uplift and climate aridification occurred in the Junggar Basin during deposition of the Qigu Formation in the Late Jurassic, while the basin began to experience a relatively humid climate and underwent rapid subsidence during deposition of the Kalazha Formation in the latest Jurassic-earliest Cretaceous, probably driven by the far-field effects of the short-lived but significant Mongol-Okhotsk collisional orogeny.

New Jurassic clam shrimps have been discovered respectively from the Hettangian lower part of the Badaowan Formation in the Junggar Basin, and the Oxfordian upper part of the Qiketai Formation in the Turpan Basin of Xinjiang, northwestern China. Through the examination under a scanning electron microscope (SEM) of well-preserved specimens we have described a new genus Punctatestheria n. gen., which includes two new species P. lianmuqinensis n. gen. n. sp. and P. karamayensis n. gen. n. sp. Given their similar punctate carapace ornamentation pattern, the British Bajocian athonian species Euestheria trotternishensis is herein attributed to the new genus. Punctatestheria n. gen. first occurred in the Hettangian and ranged into the Oxfordian. This finding supports the previous hypothesis that punctatestheriids have first derived from the Triassic lineage Aquilonoglypta , and then gave rise to triglyptids in the Bathonian, because in Triglypta three kinds of ornaments have ontogenetically developed on the carapace, the juvenile-stage dorsal part of which is ornamented by evenly distributed puncta.

61Braided delta in the Junggar basin formed in a shallow water condition with stable tectonic movement, gentle slope gradient, and wide basin.61The shallow water braided delta is characterized by02coarse grain size, large cross bedding, discontinuous normal rhythms, high02sand ratio,02distributary channels with minor mouth bars, and02progradational seismic reflections.61Sedimentary model of the shallow water delta is significant for predicting the distribution of lithologic traps in hydrocarbon exploration.

The northern Bogdashan is located in the south of the Junggar Basin and in the north of Tian Shan. Paleocurrents analysis reveals that paleocurrent direction had three important abrupt transformations from the Neopaleozoic to the Cenozoic. Before the Late Carboniferous, the paleocurrent directions were from north to south. During the Permian, the paleocurrent directions were from west to east or form northwest to southeast. From the Triassic Period to the Jurassic, the paleocurrent directions were from north to south. From the Cretaceous to the Cenozoic, the paleocurrent directions was form south to north. The northern Bogodashan may be divided four tectonic evolution stages form the Neopaleozoic to the Cenozoic by integrated analysis paleocurrent,provenance and sidimentary environment. The transition phase of paleocurrent directions was not only the boundary of each stages of basin tectonic evolution but also important sedimentary record of orogenic belt evolution around the area. Furthermore, the transition time of the paleocurrent directions may restricts when structural belt around Bogodashan had uplifted. At the end of the late Carboniferous, the north western Junggar Basin had be intensity uplift and subsequently sediments fluxes into the basin form west to east. At begin of the Triassic Period, the northern jungar basin was uplifted and it provided clastic sediments for basin from the Triassic to the Jurassic. At the end of the Jurassic, the Bogodashan began to be uplifted and provided clastic sediments for besides of the Bogodashan. Why had the orogenic belt be uplifted clockwise around of the Junggar Basin? It would be researched further.

In central and southern Junggar basin,Jurassic source rock is characterized by the large thickness,widespread,whose partial interval have well potential hydrocarbon and exploration.Based on the former study,according to the organic geochemistry and organic petrology experiment analysis method,the distribution characteristics,hydrocarbon potential,biomarker geochemistry and sedimentary environment have been investigated.The results indicate that in western Well Pen 1 depression,the Jurassic formation source rock has worse hydrocarbon potential,in Shawan depression,the Badaowan Formation and Xishanyao Formation have better hydrocarbon potential,but Sangonghe Formation source rock is worse.In Sikeshu depression,Badaowan Formation source rock has better hydrocarbon potential.Additionally,in earlier sedimentary period of Badaowan Formation,the research area developed delta front sub-facies and shore shallow lake facies.In Shawan depression,the formation developed shore shallow facies and limnetic facies with much organic matter input.The source rock is formed in weak oxidation-strong weak sedimentary environment with high plant input.In Sangonghe Formation sedimentary period,the study area distributed shore shallow lake faices,whose source rock is formed in strong oxidation environment with lacustrine high plant input.In Xishanyao Formation sedimentary period,in Mahu depression,Luliang uplift,and Western Well Pen 1 depression distributed delta plain facies and front plain facies.The sedimentary centre moved to eastern and southern depression with sub-deep lake facies,whose source rock is formed in weak oxidation-strong oxidation environment with high lacustrine plant input.

Combined with few well drilling and well logging data,and results of previous studies,sequence stratigraphy characteristics and coal accumulation controlling factors of Middle-Lower Jurassic coal-bearing series in south margins of Junggar Basin have been analyzed on the basis of sequence stratigraphic study in outcrops. Middle-Lower Jurassic coal-bearing series in south margins of Junggar Basin can be divided into one complete 2ndorder tectonic sequence,where four 3rdorder sequences and twelve system tracts were developed inside. The results show that paleotectonic setting( weakly extensive and gentle subsidence) and paleoclimate( warm,humid,and reducing condition) were the fundamental conditions for coal-forming in Middle-Lower Jurassic. While,relative lake level changes of the 2ndorder tectonic sequence and rate of relative lake level change in the 3rdorder sequence were the major controlling factors for coal accumulation. Commercial recoverable coals,which were characterized by large thickness and stably lateral distribution in outcrops,were all developed in highstand system tract( HST). During the depositional period of SQ1,relative lake level of the 2ndorder tectonic sequence was descending,leading a lower paleo-water table,where the coals were mainly developed in the lower part of HST( ascending rate of the relative lake level in the 3rdorder sequence was moderate). The depositional period of SQ3 was the maximum flooding period of Early-Middle Jurassic, when the relative lake level of the 2ndorder tectonic sequence ascended to the highest point. coal beds were mainly developed in the middle-upper part of HST( descending rate of the relevant lake level in the 3rdorder sequence was moderate).

The Bogda Mountains, as an important intracontinental orogenic belt, are situated in the southern part of the Central Asian Orogenic Belt (CAOB), and are a key area for understanding the Mesozoic evolution of the CAOB. However, the tectonic evolution of the Bogda Mountains remains controversial during the Mesozoic Era, especially the Early to Middle Jurassic Periods. The successive Lower to Middle Jurassic strata are well preserved and exposed along the northern flank of the Western Bogda Mountains and record the uplift processes of the Bogda Mountains. In this study, we analysed sedimentary facies combined with detrital zircon U-Pb geochronology at five sections of Lower to Middle Jurassic strata to detect the tectonic evolution and changes of provenance in the Bogda area. During Early to Middle Jurassic times, the fluvial, deltaic and lacustrine environments dominated in the western section of the Bogda area. The existence of Early Triassic peak age indicates that the Bogda Mountains did not experience uplift during the period of early Badaowan Formation deposition. The Early Triassic to Late Permian granitoid plutons and Carboniferous volcanic rocks from the Barkol and Santanghu areas were the main provenances. The significant change in the U-Pb age spectrum implies that the Eastern Bogda Mountains initiated uplift in the period of late Badaowan Formation deposition, and the Eastern Junggar Basin and the Turpan-Hami Basin were partially partitioned. The Eastern Bogda Mountains gradually became the major provenance. From the period of early Sangonghe to early Toutunhe Formations deposition, the provenance of the sediments and basin-range frame were similar to that of late Badaowan. However, the Eastern Bogda Mountains suffered intermittent uplift three times, and successive denudation. The uplifts respectively happened in early Sangonghe, late Sangonghe to early Xishanyao, and late Xishanyao to early Toutunhe. During the deposition stage of Toutunhe Formation, a relatively strong tectonic reactivation took place along the Late Palaeozoic Bogda rift belt accompanied by relatively large-scale magmatism. The distinct basement structure between the eastern and western Bogda rift could be the structure basis of difference uplift in the Bogda area during the Mesozoic Era. The Early to Middle Jurassic episodic uplift of Eastern Bogda Mountains perhaps was related to the post-collisional convergence of the Qiangtang Block from late Badaowan to early Sangonghe, the closure of the western Mongol-Okhotsk Ocean at the Early-Middle Jurassic boundary and the tectonic accretion at the south Asian margin of Pamir Block during late Middle Jurassic times.

The Bogda Shan, located on the northern margin of East Tianshan, forms the watershed between the Junggar basin and the Chaiwopu depression. Its initial uplift time has been debated for a long time, and is of important geotectonic significance.Field surveys and seismic exploration show that the lowest regional angular unconformity older than the Carboniferous developed between the Cretaceous and the pre-Cretaceous strata. Several measurements have been made of cross-bedding and stoss surfaces of imbricate pebbles. Statistical analysis of the data indicates that a major change in sediment dispersal pattern occurred at the end of the Jurassic or the beginning of the Cretaceous. In the Jurassic, the sediment dispersal pattern is convergent, and the Bogda area functioned as a water catchment. In the Cretaceous, the sediment dispersal pattern is divergent, and the Bogda area functioned as a watershed. A statistical study of the composition of clasts in the Jurassic and Cretaceous conglomerates suggests that these Cretaceous conglomerates are different from the Jurassic conglomerates, and are composed mainly of volcanic gravels derived from nearby areas. On the basis of these studies we conclude that the initial uplift of Bogda Shan took place between the latest Jurassic and the earliest Cretaceous.Therefore we suggest that 1the Bogda Shan is not an integral part of the Tianshan orogenic belt; and 2 the Chaiwopu depression is part of the early Mesozoic Junggar Basin.

Based on previous data,field investigation in Bogda area and systematic study on petrology,stratigraphy and sedimentation of Bogda tectonic belt we consider that Bogda mountain area was exposed to the early carboniferous initial rift evolution,late carboniferous mature rift valley evolution,the early Permian orogenic evolution and the late early Permian post-orogenic evolution.

Based on the analysis of heavy mineral assemblages in Cenozoic southwestern Qaidam Basin, we found that different areas have variable heavy mineral assemblage characteristics, which suggested that there were two source areas he Altyn Mountains and the Qimen Tagh-East Kunlun Mountains. In Ganchaigou-Shizigou-Huatugou (Area A), which was mainly source from the Altyn Mountains, its heavy minerals were mainly composed of zircon, Ti-oxides, and wollastonite in the Paleocene-early Eocene and mainly of unstable minerals, especially amphibole, in the middle Eocene-Oligene. Since the late Oligocene-Miocene, the heavy minerals were still mainly unstable minerals, but the content of epidote increased and the content of amphibole decreased. In Qigequan-Hongliuquan (Area B), which was the mixed source from the Altyn Mountains and the Qimen Tagh-East Kunlun Mountains, its heavy minerals were mainly garnet, epidote, and amphibole. The source of L caotan-Dongchaishan-Kunbei (Area C) was mainly from the Qimen Tagh-East Kunlun Mountains, heavy minerals in the sediments in Area C were mainly zircon and Ti-oxides in Paleogene and garnet, epidote, and amphibole in Neogene. In Yuejin-Youshashan (Area D), where the stable minerals and unstable minerals were present simultaneously, the heavy mineral assemblages was controlled by multi-direction source. The variation of heavy mineral assemblages in southwestern Qaidam Basin shows that Altyn Mountains was of low-lying topographic relief in Paleocene-early Eocene, and the rapid uplift of Altyn Mountains started from the middle Eocene. In Paleogene, the Altyn Tagh Fault had a slow strike-slip velocity, but the strike-slip velocity increased greatly since the late Oligocene, leading to a strike-slip displacement above 300 km since Neogene. Meanwhile, the Qimen Tagh-East Kunlun fault zone was under a stable tectonic stage in Paleogene with the Qimen Tagh Mountain being low-lying hills; since the late Oligocene, the fault zone started to activate and the Qimen Tagh Mountain began to uplift rapidly.

There are abundant hydrocarbon resources on the southern margin of Junggar Basin; nevertheless,most of the oil and gas fields were found only in the shallow layer,and the oil and gas reservoirs are very limited. The exploration of the middle-low layers has not made breakthrough. In order to expand the area of exploration,researchers have made lots of studies which are mainly focused on the structural styles. For the purpose of solving this problem,the authors emphatically investigated the reservoir characteristics and the controlling factors of deep reservoirs. Detailed information was acquired by the authors by using such means as casting thin sec tions,scanning electron microscope(SEM),permeability and porosity test,and fluid inclusion test,combined with carbon and oxygen isotope analysis and vitrinite reflectance(Ro). Studies show that the favorable areas of deep reservoirs are controlled by the sedimentary facies,the distal bars are the best reservoirs in Qingshuihe Formation,and the effective reservoirs of Qigu Formation are located in the upper part of distributary channel sand bodies. The lower paleogeothermal gradient,the less influence of regional tectonic stress and the quick burial in late period of burial process have greatly improved the deep reservoirs on the south margin of Junggar Basin.

Based on systematic analysis of conglomerate constituent,paleocurrent direction,detrital composition,heavy mineral and major element,the provenance characteristics of Shuixigou Group in southern margin of Junggar Basin are studied.The analysis of conglomerate component of Shuixigou Group shows that Yilinhabierga Mountain,northern Tianshan Mountains and northern margin fault of central Tianshan Mountains were the source areas in the sedimentary period of Badaowan and Xishanyao Formation.The paleocurrent analytical data of Shuixigou Group show that paleocurrent directions of Badaowan Formation and Xishanyao Formation are mainly northeast and west,so Yilinhabierga Mountain is the primary source area.The paleocurrent directions of Sangonghe Formation are mainly SSW and SE, which indicates that Bogda Mountain and Yilinhabierga Mountain are not the primary source area in that period. Shuixigou Group in the western and eastern segment of the southern margin of Junggar Basin has heavy mineral assemblage of basic magmatic rocks,which shows that the material supply might be from the northern Tianshan Mountains.The middle segment of the southern margin of Junggar Basin has genetic features of medium-acidic magmatite and basic magmatic rocks,which shows that the source area is in Bogda Mountain.

Junggar basin is one of the largest petroliferous basins in China,although a series of oil and gas fields had been found in the south of the basin,the oil-gas exploration in the fore mountain belt of Bogda Mountain did not make great breakthroughs. The reason may be associated with the few awareness of the evolution of the Bogda Mountain to control,restrain the evolution of the late peripheral sags and the hydrocarbon generation and the basin formation. The conservative fragmentary materials in sedimentary basins had recorded the lithosphere features of the orogenic belts at the margin of the South China block and kinetics characterization of basins during the sedimentary evolution. At the same time,as sedimentary heavy minerals were very stable and they had been participating in this long and complicated geological processes,which could provide the important information to the source rocks. Thus,in this text,based on the mineral petrology characteristics of heavy minerals,such as roundings,content changes,combination features and the different heavy mineral indexes,to study the uplift processes of Bogda Mountain in the period of Jurassic,which could provide strong evidence that Bogda Mountain uplifted in Toutunhe Formation of Middle Jurassic. Moreover,according to the features of heavy minerals,the tectonic evolution stages of Bogda Mountain during Jurassic period were divided into two parts: 1) from early Jurassic to the late period of middle Jurassic,the tectonic evolution was relatively stable,and 2) from the late period of middle Jurassic to late Jurassic,tectonic uplifting was strong. In addition,combined with the previous research results such as tectono-thermochronology,U-Pb age and paleocurrent,we considered that the provenances of Bogda area were from Kalameili Montain during early Jurassic to the late period of middle Jurassic and Bogda Mountain during the late period of middle Jurassic to late Jurassic. And that,in the later period,the Bogda Mountain had been uplifted.

The tectonic evolution of the Tian Shan, as for most ranges in continental Asia is dominated by north-south compression since the Cenozoic India-Asia collision. However, precollision governing tectonic processes remain enigmatic. An excellent record is provided by thick Palaeozoic – Cenozoic lacustrine to fluvial depositional sequences that are well preserved in the southern margin of the Junggar Basin and exposed along a foreland basin associated to the Late Cenozoic rejuvenation of the Tian Shan ranges. U/Pb (LA-ICP-MS) dating of detrital zircons from 14 sandstone samples from a continuous series ranging in age from latest Palaeozoic to Quaternary is used to investigate changes in sediment provenance through time and to correlate them with major tectonic phases in the range. Samples were systematically collected along two nearby sections in the foreland basin. The results show that the detrital zircons are mostly magmatic in origin, with some minor input from metamorphic zircons. The U-Pb detrital zircon ages range widely from 127 to 2856 Ma and can be divided into four main groups: 127–197 (sub-peak at 159 Ma), 250–379 (sub-peak at 318 Ma), 381–538 (sub-peak at 406 Ma) and 543–2856 Ma (sub-peak at 912 Ma). These groups indicate that the zircons were largely derived from the Tian Shan area to the south since a Late Carboniferous basin initiation. The provenance and basin-range pattern evolution of the southern margin of Junggar Basin can be generally divided into four stages: (1) Late Carboniferous – Early Triassic basin evolution in a half-graben or post-orogenic extensional context; (2) From Middle Triassic to Upper Jurassic times, the southern Junggar became a passively subsiding basin until (3) being inverted during Lower Cretaceous – Palaeogene; (4) During the Neogene, a piedmont developed along the northern margin of the North Tian Shan block and Junggar Basin became a true foreland basin.

Jurassic source rocks in the Junggar Basin (NW China) include coal swamp and freshwater lacustrine deposits. Hydrocarbon-generating macerals in the coal swamp deposits are dominated by desmocollinite and exinite of higher-plant origin. In lacustrine facies, macerals consists of bacterially-altered amorphinite, algal- amorphinite, alginite, exinite and vitrinite. Coals and coaly mudstones in the Lower Jurassic Badaowan Formation generate oil at the Qigu oilfield on the southern margin of the basin. Lacustrine source rocks generate oil at the Cainan oilfield in the centre of the basin.

Junggar Basin, located in northern Xinjiang, presents continuous and multikilometer-thick strata of the Jurassic deposits. The Jurassic was entirely terrestrial fluvial and lacustrine deltaic sedimentation. Eight outcrop sections across the Jurassic strata were measured at a resolution of meters in southern Junggar Basin. Controlling factors of sedimentary evolution and palaeoclimate changes in Junggar Basin during the Jurassic were discussed based on lithology, fossils and tectonic setting. In the Early to Middle Jurassic, the warm and wide Tethys Sea generated a strong monsoonal circulation over the central Asian continent, and provided adequate moisture for Junggar Basin. Coal-bearing strata of the Badaowan, Sangonghe, and Xishanyao Formations were developed under warm and humid palaeoclimate in Junggar Basin. In the late Middle Jurassic, Junggar Basin was in a semi-humid and semi-arid environment due to global warming event. Stratigraphy in the upper part of the Middle Jurassic with less plant fossils became multicolor or reddish from dark color sediments. During the Late Jurassic, collision of Lhasa and Qiangtang Block obstructed monsoon from the Tethys Sea. A major change in climate from semi-humid and semi-arid to arid conditions took place, and reddish strata of the Upper Jurassic were developed across Junggar Basin.

Random forests (RF) has become a popular technique for classification, prediction, studying variable importance, variable selection, and outlier detection. There are numerous application examples of RF in a variety of fields. Several large scale comparisons including RF have been performed. There are numerous articles, where variable importance evaluations based on the variable importance measures available from RF are used for data exploration and understanding. Apart from the literature survey in RF area, this paper also presents results of new tests regarding variable rankings based on RF variable importance measures. We studied experimentally the consistency and generality of such rankings. Results of the studies indicate that there is no evidence supporting the belief in generality of such rankings. A high variance of variable importance evaluations was observed in the case of small number of trees and small data sets.

Land cover monitoring using remotely sensed data requires robust classification methods which allow for the accurate mapping of complex land cover and land use categories. Random forest (RF) is a powerful machine learning classifier that is relatively unknown in land remote sensing and has not been evaluated thoroughly by the remote sensing community compared to more conventional pattern recognition techniques. Key advantages of RF include: their non-parametric nature; high classification accuracy; and capability to determine variable importance. However, the split rules for classification are unknown, therefore RF can be considered to be black box type classifier. RF provides an algorithm for estimating missing values; and flexibility to perform several types of data analysis, including regression, classification, survival analysis, and unsupervised learning. In this paper, the performance of the RF classifier for land cover classification of a complex area is explored. Evaluation was based on several criteria: mapping accuracy, sensitivity to data set size and noise. Landsat-5 Thematic Mapper data captured in European spring and summer were used with auxiliary variables derived from a digital terrain model to classify 14 different land categories in the south of Spain. Results show that the RF algorithm yields accurate land cover classifications, with 92% overall accuracy and a Kappa index of 0.92. RF is robust to training data reduction and noise because significant differences in kappa values were only observed for data reduction and noise addition values greater than 50 and 20%, respectively. Additionally, variables that RF identified as most important for classifying land cover coincided with expectations. A McNemar test indicates an overall better performance of the random forest model over a single decision tree at the 0.00001 significance level.

Apatite fission track analysis and thermal history modeling of nine sandstone samples collected from diverse structure belts of the Bogda Mountain reveal an orogenic process of upper crust and a differential exhumation history of the Bogda Mountain since Late Mesozoic. The orogenic process of upper crust of the Bogda Mountain is characterized by that the propagation sequences of thrust structures are piggyback within the detached belt and overstep within the basement-involved belt. Main tectonic uplifts of the Bogda Mountain since Late Mesozoic occurred at 155～135Ma, 90～70Ma,～40Ma and～10Ma, respectively. Correspondingly, uplift and exhumation history of the Bogda Mountain experienced three main stages, e.g. an initially integral uplift stage at the Early Yanshan epoch (with 0.83～1.2 km of amount denuded), a slow elevation stage at the Late Yanshan epoch (with 0.68～0.83 km of amount denuded) and a tremendously differential exhumation at the Late Himalayan epoch (with ～5.0 km of amount denuded in the overthrust belt, 1.82～3.18 km in the basement involved belt, and ～2.73 km in the detachment belt, respectively. The detachment belt presents characters of rapider cooling and higher denudation ratio due to a later starting exhumation time. Regional deformation was closely related to collision and accretion of the terrains in the south Asian continental margin since Late Mesozoic.

Middle-Cambrian to Permian subduction-related records are widely distributed in Northern Xinjiang which can be grouped into the Chinese Altay–East Junggar–Eastern Tien Shan, West Junggar, Yili, and Tarim domains. By integrating paleogeographic and geological data, we suppose that the Chinese Altay–East Junggar–Eastern Tien Shan domain was more closely located to Siberia, while the West Junggar and Yili domains occupied an intermediate position near the Kazakhstan block in the early Paleozoic Paleoasian Ocean. Distribution of Andean-type magmatic arcs, island arcs, accretionary wedges, ophiolitic slices, and/or microcontinents shows an archipelago paleogeography forming a huge accretionary active margin sequences. The Tarim domain was on the opposite side of the early Paleozoic Paleoasian Ocean remaining passive margin. These tectonic units drifted northwards and approached the southern active margin of the Siberian craton in the late Paleozoic, leading to termination of the Paleoasian Ocean and formation of a complicated orogenic collage between Siberian craton and the Tarim block between the end-Permian and Triassic. These multiple accretion processes significantly contributed to the lateral growth of central Asia.

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Late Carboniferous to Early Permian is a critical period for the final amalgamation of the Central Asian Orogenic Belt (CAOB). However, as most of the accreted terranes of the CAOB are unclear in tectonic nature and origin, the timing and processes of their mutual amalgamation have been poorly constrained. To understand assembly of the West Junggar Terrane with the Yili Block, a suite of the late Paleozoic magmatic rocks, including ignimbrite, rhyolite and granite, in northwestern Chinese Tianshan Belt were studied for their petrogenesis and tectonic implications. Our new results of secondary ion mass spectrometry (SIMS) zircon U-Pb dating reveal two separate magmatic episodes, ca. 30002Ma volcanism (ignimbrite and rhyolite) and ca. 28802Ma plutonsim (biotite granite). Geochemically, for the ca. 30002Ma volcanism, the ignimbrites have low SiO 2 (65.8–71.502wt.%) and Mg # (6–13) values, and exhibit arc affinity with significantly enriched in large ion lithophile elements (LILE) and depleted in high field strength elements (HFSE) such as Nb, Ta and Ti. The whole-rock ε Nd (t) and zircon ε Hf (t) values range from +6.9 to +7.0 and +9.9 to +14.1 respectively, indicating a juvenile basaltic lower crustal origin. Rhyolites have slightly high SiO 2 (72.7–74.002wt.%) and K 2 O (3.86–4.5302wt.%) contents, high zircon δ 18 O (11.67–13.23‰) values, and low whole-rock ε Nd (t) (+2.9 to +3.8) and zircon ε Hf (t) (+2.8 to +10.0) values, which may suggest sediment involvements during magma generation. In contrast, for the ca. 28802Ma plutonism, the biotite granites have obviously higher SiO 2 (74.7–75.502wt.%) contents and whole-rock ε Nd (t) (+7.7 to +8.8), zircon ε Hf (t) (+9.8 to +12.7), and lower zircon δ 18 O (5.99–6.84‰) values, than those of the ca. 30002Ma volcanic rocks, which are consistent with signatures of juvenile magma source. According to our estimates of zircon saturation temperatures, together with their contrasting genesis, we attribute the formation of ca. 30002Ma high temperature (815–93802°C) volcanism to oceanic slab break-off during assembly of the West Junggar Terrane with the Yili Block, and relate the generation of ca. 28802Ma low temperature (723–73502°C) plutonism to subsequent strike-slipping of North Tianshan Fault that facilitated introduction of water-fluxes triggering hydrous partial melting of juvenile lower crust. The sequential magmatic episodes in the northwestern Chinese Tianshan Belt may provide a crucial clue to a tectonic transition from plate convergence to intra-plate adjustment during the formation of the Kazakhstan Orocline in the late Paleozoic.

The Late Paleozoic magmatic evolution of the Bogda Range (Chinese North Tianshan) is important for understanding the accretionary history of the Central Asian Orogenic Belt. We investigated the Carboniferous and Lower Permian volcanic and sedimentary sequences of the Daheyan section, southern Bogda Range, and present new zircon U-Pb ages and whole-rock geochemical data for the volcanic rocks. One Carboniferous rhyolite is dated at 298 8 Ma; a Permian basalt yielded many Proterozoic zircon xenocrysts, and its maximum age ( 297 Ma) is constrained by the detrital zircon ages of the sandstone that stratigraphically underlies it. These volcanic rocks belong to calc-alkaline series. We further synthesize previous geochronological, geochemical and isotopic data of magmatic and sedimentary rocks in the Bogda Range. The available data indicate that the magmatism occurred continuously from 350 Ma to 280 Ma. A comprehensive analysis allows us to propose that: (1) the Carboniferous to Early Permian magmatic rocks of the Bogda Range generally show consistent arc-type features; (2) increasing mantle input through time suggests intra-arc extension in a supra-subduction zone; (3) the localized occurrence of Early Permian alkaline pillow basalts and deep water sediments close to the major shear zone advocate a transtensional crustal thinning during the transition from Carboniferous convergence to Early Permian transcurrent tectonics; (4) occurrence of a large number of Proterozoic zircon xenocrysts in the Late Paleozoic magmatic rocks, and Proterozoic detrital zircons in the coeval clastic sediments suggest a continental or transitional basement of the Bogda Arc; (5) subduction in the Bogda area terminated prior to the deposition of Middle Permian terrestrial sediments.

The Chinese Tien Shan range is a Palaeozoic orogenic belt which contains two collision zones. The older, southern collision accreted a north-facing passive continental margin on the north side of the Tarim Block to an active continental margin on the south side of an elongate continental tract, the Central Tien Shan. Collision occurred along the Qinbulak-Qawabulak Fault (Southern Tien Shan suture). The time of the collision is poorly constrained, but was probably in in the Late Devonian-Early Carboniferous. We propose this age because of a major disconformity at this time along the north side of the Tarim Block, and because the Youshugou ophiolite is imbricated with Middle Devonian sediments. A younger, probably Late Carboniferous-Early Permian collision along the North Tien Shan Fault (Northern Tien Shan suture) accreted the northern side of the Central Tien Shan to an island arc which lay to its north, the North Tien Shan arc. This collision is bracketed by the Middle Carboniferous termination of arc magmatism and the appearance of Late Carboniferous or Early Permian elastics in a foreland basin developed over the extinct arc. Thrust sheets generated by the collision are proposed as the tectonic load responsible for the subsidence of this basin. Post-collisional, but Palaeozoic, dextral shear occurred along the northern suture zone, this was accompanied by the intrusion of basic and acidic magmas in the Central Tien Shan. Late Palaeozoic basic igneous rocks from all three lithospheric blocks represented in the Tien Shan possess chemical characteristics associated with generation in supra-subduction zone environments, even though many post-date one or both collisions. Rocks from each block also possess distinctive trace element chemistries, which supports the three-fold structural division of the orogenic belt. It is unclear whether the chemical differences represent different source characteristics, or are due to different episodes of magmatism being juxtaposed by later dextral strike-slip fault motions. Because the southern collision zone in the Tien Shan is the older of the two, the Tarim Block sensu stricto collided not with the Eurasian landmass, but with a continental block which was itself separated from Eurasia by at least one ocean. The destruction of this ocean in Late Carboniferous-Early Permian times represented the final elimination of all oceanic basins from this part of central Asia.

61Provenance of the southern Junggar Basin in the Jurassic.61Combine detrital zircon U-Pb ages with depositional environments.61Confirm a late Jurassic volcanic activity in the Tian Shan.

Aim To study the geochemistry characteristics,zircon U-Pb chronology and the geological significance of the K-feldspar granite in northern Baluntai area.Methods Based on the geological investigation,geochemistry analysis and LA-ICP-MS zircon U-Pb dating about the K-feldspar granite,the geological significance of the K-feldspar granite has been studied.Results The K-feldspar granite has the characteristics of island-arc granites,and formed at 369.5 Ma 2.6 Ma.Conclusion The paleo-southern Tianshan ocean lithosphere had been subducting beneath the Yili-middle Tianshan block from Silurian to late Devonian.

61Early Carboniferous volcanic rocks in the Kalamaili orogen are post-collisional.61Post-collisional setting started in Tournaisian in East Junggar.61Slab breakoff at 34563330Ma was the geodynamic process producing volcanism.613 groups of mafic rocks from calc-alkaline to potassic alkaline are interpreted.

61Indicate the types and dispersal characteristics of provenance systems quantitatively.61Identify the facies characteristics of the beach and bar sandbodies.61Reveal the planar dispersal patterns of beach-bar sedimentary systems and their spatial-temporal evolution.

Mesozoic basins in different regions of Central Asia provide important records for investigating relationships between intraplate deformation in Central Asia and tectonic processes at Asian boundaries. The present study gives a review of the stratigraphic and structural evolution of basins in different regions of Central Asia during the Middle-Late Jurassic. It is shown that basins and mountain belts in northwest China experienced compressional deformation and were wholly or partially uplifted during the late Middle-Late Jurassic. Compared to extensively-distributed Middle Jurassic coal-bearing strata in northwest China, Upper Jurassic strata characterized by red mudstones and conglomerates have a much smaller distribution. In the mean time, the Tibet-Pamir plateau also underwent a folding and uplift event, and Upper Jurassic sedimentary rocks are generally missing in the Pamir and western Tibet. The intense compressional deformation and uplift event of the late Middle-Late Jurassic from the Tibet-Pamir plateau to northwest China requires a new tectonic model, as proposed here. We suggest that the Karakoram and Lhasa blocks were a single giant block, which was accreted to Asia in the late Middle Jurassic-earliest Cretaceous and cross-cut by the Karakoram Fault in the Cenozoic. During the Callovian, the western part of the Karakoram-Lhasa Block initially collided with the southern Asian margin. Collision and continued convergence during the late Middle-Late Jurassic caused sinistral strike-slip faulting along the Central Badakhshan Fault and South Tian Shan Suture, accommodating crustal shortening in areas to the southeast of the faults: the Pamir, western Tibet, Tarim Block, Qilian-Qaidam Block, and Bei Shan. Meanwhile, the northeastward transpressional motion of the Tarim Block produced strong compressional stresses to areas north of the Tarim Block: the Kyrgyz Tian Shan, Central Tian Shan, Junggar Basin, and Turfan Basin. With the northward movement of the Karakoram-Lhasa Block, the eastern part of the Karakoram-Lhasa Block began to collide with the southern Asian margin during the latest Jurassic-earliest Cretaceous, resulting in strong crustal deformation and thickening in East Asia and Central Asia.

Apatite fission-track data indicate that Mesozoic strata exposed on the northern flank of the Chinese Tian Shan underwent 藴4-5 km of late Cenozoic unroofing, beginning at 24 Ma. This age apparently dates initial reactivation of the northern Tian Shan in response to the India-Asia collision, which continues to raise the mountain range today. Numerous studies of the Himalaya and Tibet suggest that a major shift from extrusion-dominated to crustal thickening-dominated tectonics occurred in latest Oligocene-early Miocene time, approximately coincident with the start of unroofing in the Tian Shan. This suggests that Tian Shan unroofing was a distant effect of that shift within the collision zone.

61Provenances in the Bogda area changed noticeably from the Permian to the Jurassic.61Evolution of basin pattern is consistent with geological setting of this area.61The Bogda area had a very gentle positive relief in the Early Jurassic.61The Bogda Mountains became a major provenance during the Middle-Late Jurassic.

The middle and lower Jurassic in southern margin area of Junggar basin was divided into 5 sequences based on analyses of exploration lines,well,logging curve,paleontology,field outcrop profiles and seismic reflective.Lowstand,lacustrine transgressive and highstand systems tracts were subdivided by the stacking patterns of stratigraphy,changes of lithology and lithofacies.The sequence stratigraphic correlation in well-tie sections made it possible to construct the regional stratigraphic framework.Fan delta,delta,lacustrine and peat swamp sedimentary system facies were identified by fully applying the drilling,logging,palaeontology and field outcrop profiles data.The architecture,evolution,distribution of sedimentary faces of the middle and lower Jurassic in southern margin area of Junggar Basin was analyzed.The coal-accumulation features in sequence stratigraphic framework was clarified.Coal bed vertical distribution was controlled by the sequence architecture pattern.Coal bed is developed in the early lowstand systems tract and in the late highstand systems tract,and coal bed transverse distribution is controlled by the sedimentary environment.